Wiper blade partial pressure setting method

Abstract

A backing of a wiper blade ( 53 ) is virtually divided into a plurality of regions in a longitudinal direction of the backing. A wiping area (B) of the wiper blade ( 53 ) in a glass surface ( 50 a ) is discretized in a wiping direction (x direction) of the wiper blade ( 53 ) and in a longitudinal direction (z direction) of the wiper blade ( 53 ). A curvature of each of the plurality of virtually divided regions of the backing is set in such a manner that a sum of variation differences of contact pressures (Fyij) at respective discretized points (Pij) is minimized. With such a wiper blade partial pressure setting method, a wiping performance of the wiper blade ( 53 ) can be easily and reliably improved over the entire wiping area of the wiping surface.

1. A wiper blade partial pressure setting method for a wiper blade that includes a backing, which is received in a blade rubber that wipes a wiping surface, wherein the backing spreads an urging force applied from a wiper arm toward the wiping surface in a longitudinal direction of the blade rubber to unify contact pressures of the blade rubber against the wiping surface, the wiper blade partial pressure setting method comprising:
 virtually dividing the backing into a plurality of regions in a longitudinal direction of the backing; 
 discretizing a wiping area of the wiper blade in the wiping surface in a wiping direction of the wiper blade and in a longitudinal direction of the wiper blade; and 
 setting at least one of a curvature and a rigidity of each of the plurality of virtually divided regions of the backing in such a manner that a sum of variation differences of the contact pressures at respective discretized points is minimized. 
 
   
   
     2. The wiper blade partial pressure setting method according to  claim 1 , wherein
 the sum of the variation differences of the contact pressures is: 
 a sum of absolute values of differences, each of which is between the contact pressure at a corresponding one of the discretized points and a reference value; or 
 a sum of squares of the differences, each of which is between the contact pressure at the corresponding one of the discretized points and the reference value. 
 
   
   
     3. The wiper blade partial pressure setting method according to  claim 1 , further comprising
 weighting according to the variation differences of the contact pressures. 
 
   
   
     4. The wiper blade partial pressure setting method according to  claim 1 , wherein
 the sum of the variation differences of the contact pressures is a sum of the variation differences of the contact pressures computed for a round-trip of the wiper blade in the wiping direction. 
 
   
   
     5. The wiper blade partial pressure setting method according to  claim 1 , wherein
 the discretizing of the wiping area of the wiper blade includes: 
 dividing the wiping area into equal intervals in the wiping direction of the wiper blade; and 
 dividing the wiping area into equal intervals in the longitudinal direction of the wiper blade. 
 
   
   
     6. The wiper blade partial pressure setting method according to  claim 1 , wherein
 the virtually dividing of the backing includes dividing the backing into equal intervals in the longitudinal direction of the backing.